为什么 jupyter 有时会打印格式化的 DataFrame，有时会打印为文本？

Question

I have the following code in a jupypter notebook:

# (1) How to add a new column?
test_csv['aggregator'] = None
print (test_csv)

# (2) How to remove a column?
test_csv.drop(columns=['platform'])

It prints the following:

Why is the second statement formatted tabularly (without a print statement) whereas the first one is just text data? Is there a way to force print-format the DataFrame with the nicely-formatted table applied?

Answer 1

test_csv.drop(columns=['platform']) does not actually drop the column. It just shows you the interim picture of dataframe by printing its state.

To actually drop the column:

test_csv.drop(columns=['platform'], inplace=True)

OR

test_csv.drop('platform', axis=1, inplace=True)

test_csv['aggregator'] = None changes the state of the dataframe by assigning a new column to it. Hence, it does not print anything.

Answer 2

Why does jupyter sometimes print a DataFrame formatted and sometimes as text?

if you use the function - print it will print it as text because print is using the function to_string for any object it gets.

and when you "leave" the data frame at the and of the cell it will show it as a table because it one of the functions that Jupiter does.

the function test_csv.drop(columns=['platform']) returns df if you want it to do the drop in the dataFrame you have to use inplace=True or df=df.drop(col)... and than print the dataFrame

Answer 3

I think you are running both the statements in the same cell of the Jupyter Notebook

You can run the below snippet in one cell

# (1) How to add a new column?
test_csv['aggregator'] = None
test_csv # no need to use print

and in the other cell

# (2) How to remove a column?
test_csv.drop(columns=['platform'])